NEW YORK >> Back in spring training when the Dodgers’ farm system had been hailed by Baseball America as the best, Dodgers GM Farhan Zaidi said “we’re not putting that trophy in the trophy case,” pointing towards bigger goals to be achieved on the field.

However, any of the goals the Dodgers do achieve – like a fourth consecutive National League West title – will owe a great deal to the products of that top-rated farm system. Through Monday’s win at Yankee Stadium, rookies have pitched 28.5 percent of the Dodgers’ innings this season and made 21.3 percent of the plate appearances. Two rookies were in the starting lineup Monday (Corey Seager and Andrew Toles) and another started on the mound (Jose De Leon).

“We would be probably on the outside looking in (without the contribution of rookies),” Dodgers manager Dave Roberts said. “And I think right now we’re in a pretty good spot and I think a lot of it is largely from the contributions of these young players.

“The front office and myself — a lot of the conversations we had (in the spring) with development was about how deep we are. But obviously their ascension has been accelerated. We knew we had real depth and real players. But I just didn’t see them making the impact they’ve made.”

Seager’s impact has been the most obvious. A shoo-in now to win the National League Rookie of the Year award (the Dodgers’ 17th), Seager has already set the LA franchise record for runs and doubles by a rookie and figures to add hits, on-base percentage and possibly batting average as well.

On the mound, rookies have been the duct tape that has held the Dodgers’ starting rotation together. De Leon’s start Monday against the Yankees was the 61st made by a rookie pitcher for the Dodgers this season (a number helped by Kenta Maeda’s rookie status in MLB). The Dodgers are 36-25 in those games and Roberts will start another rookie, left-hander Julio Urias, Tuesday at Yankee Stadium.

“I was talking to him about it, going back-to-back here,” De Leon said. “We went back-to-back last year in (Double-A) Tulsa. I don’t think we did it in Oklahoma (Triple-A) this year.”

Yankee Stadium is not where Roberts expected De Leon and Urias to be in September.

“No. I thought Jose might be somewhere in Puerto Rico (his home) doing something and Julio might be up here kind of watching Major League Baseball,” Roberts joked. “To see the impact these guys have made along with Brock Stewart and Ross Stripling, it’s fascinating. And, no, I wouldn’t have envisioned it.”

Five months into the season, though, Roberts has no hesitation about sending two rookies to the mound at Yankee Stadium in the middle of a playoff race.

“I think it’s something that none of us would have really envisioned but I can’t say enough about the way these guys have stepped up to each moment,” Roberts said. “They’re just unfazed. I don’t know if it’s just the naivete of youthfulness. But the skill set is obviously there for these two young kids.

“Certainly with Julio it doesn’t seem like we’re running a rookie pitcher out there. It just seems like another one of our starters — X amount of starters that we’ve used this year (15, tied for the major-league lead). With Jose, maybe a little bit I’m thinking about knowing he’s a young player. But any reservations? I don’t think anyone in the clubhouse has any.”

Rotation roundup

Left-hander Rich Hill and Maeda will start the first two games of the Dodgers’ series in Arizona Thursday and Friday. Both will be working on regular rest for the first time in awhile. Maeda hasn’t done it since August 9 and Hill not since July 7 – the start in Houston when the blister on his middle finger ripped open.

Both will have to make their next turns on regular rest as well if the Dodgers want them to face the San Francisco Giants next week in Los Angeles. The rotation is lined up for Clayton Kershaw, Hill and Maeda to start that three-game series.

Maeda has made 18 of his 28 starts on extra rest as the Dodgers gave him extra days whenever possible during his first season in the majors, keeping his workload closer to what he was used to in Japan. Maeda is 4-3 with a 3.75 ERA and 1.21 WHIP on four days’ rest, 10-4 with a 3.02 ERA and 1.07 WHIP when working on extra rest.

Roberts would not say who will start the final two games of the series in Arizona but Ross Stripling, Brock Stewart and Bud Norris are all available.

Notes

Adrian Gonzalez started at DH in the opener of the interleague series at Yankee Stadium on Monday. Roberts said he plans to start Justin Turner at DH Tuesday against Yankees left-hander C.C. Sabathia and Andre Ethier on Wednesday against right-hander Michael Pineda. … Roberts said he plans to start Yasiel Puig in left field Tuesday.

Bill Plunkett has covered everything from rodeo to Super Bowls to boxing (yeah, I was there the night Mike Tyson bit Evander Holyfield's ear off) during a career that started far too long ago to mention and eventually brought him to the OC some time last century (1999 actually). He has been covering Major League Baseball for the Orange County Register since 2003, spending time on both the Angels and Dodgers beats.